1. Field of the Invention
This invention relates to a vaginal speculum and, more particularly, to a vaginal speculum including means providing for retraction of the lateral walls of the vagina.
2. Summary of the Background Art
A vaginal speculum is an important medical tool for providing visual access to structures within the vaginal opening, including the cervix, during a gynecological examination. A conventional vaginal speculum includes a pair of opposed blades movable between a closed position, with the opposed blades lying against one another, and an open position, with the opposed blades spaced apart from one another. During a gynecological examination, the blades of the speculum are inserted into the vagina with the opposed blades in the closed position. Then opposed blades are then opened, allowing the vagina to be visualized through an opening in a frame disposed adjacent a proximal end of the blades. Typically, the speculum additionally includes latching or screw means to hold the movable blade in its open position, or in additional positions between its closed and fully open positions.
When the conventional speculum is thus inserted and opened, its blades press upon the anterior and posterior walls of the vagina. However, since the blades do not extend along the lateral walls of the vagina, in certain patients, these lateral walls collapse inward, blocking visual examination of the vagina and cervix as required during a gynecological examination. This problem is often encountered in patients who have had multiple vaginal deliveries of babies and in obese patients. The levator and musculature of a patient who has experienced multiple vaginal deliveries may be relaxed so that the lateral vaginal walls collapse inward during the examination, with the muscles having been mechanically overstressed from the multiple deliveries and from weight gain associated with multiple pregnancies. An obese patient may present a similar problem during examination due to excessive connective tissue beneath the pelvic peritoneum. One effect of this problem is that the clinician may extend the blades of the speculum farther than otherwise necessary in an attempt to pull sagging tissue into a stretched condition, resulting in additional patient discomfort.
This problem may be alleviated by providing the speculum with an elastic sheet or membrane extending between the blades in their open position to hold the lateral vaginal wall tissue in place. For example, International Application WO 98/33431 describes the use of a sleeve of elastic material, placed over the blades or jaws of the speculum to stretch when the jaws are opened so that sleeve portions span openings between the jaws, preventing the prolapse of tissue into these openings. The sleeve can be supplied in a rolled condition for ease of application, and may have a bead at one end to assist in its removal from the speculum jaws. Alternately, as described in U.S. Pat. No. 6,432,048, loose vaginal tissue may be retained in a lateral direction by a speculum including a flexible membrane structure, such as a pair of membranes that extend between the blades. The membranes are configured to remain in a generally collapsed configuration when the blades are in the closed position to avoid interfering with insertion or withdrawal of the speculum. What is needed is a speculum having rigid surfaces for holding the prolapsed lateral tissue in place, since such surfaces do not rely on the forces necessary to stretch membranes or elastic materials sufficiently for such purposes.
Alternately, lateral vaginal sidewall tissue may be held in place with a device that expands laterally, such as the vaginal speculum described in U.S. Pat. No. 4,994,070, which has a sheet member of inherently resistant material capable of being rolled into a normal position in which the member forms a narrow, generally elongate shape. The sheet member is expandable under its inherent resilience to a dilated position in which the member forms a hollow generally open ended shape having a substantially continuous sidewall. The sheet member is provided with first and second handle members that are attached to the sheet member along left and right edges, respectively. Again, what is needed is a speculum having rigid surfaces for holding the prolapsed tissue in place, since such rigid surfaces can be shaped optimally for this purpose.
As described in U.S. Pat. No. 6,527,710, the lateral walls of the vagina may alternately be supported by a number of rounded ribs, extending parallel to one another between a stationary blade and a link fashioned as a moving blade of a speculum. Each of the ribs is pivotally attached at one end to the stationary blade and at the other end to the link. When the speculum is closed, the ribs and the link lie against the stationary blade. As the speculum is opened, the ribs pivot away from the surface of the stationary blade with the link. What is needed is a speculum having rigid surfaces for holding the prolapsed tissue in place without multiple twisting movements, which may cause patient discomfort.
U.S. Pat. Nos. 5,509,893 and 6,436,033 describe vaginal specula having four blades, comprising two pairs of blades that open in directions perpendicular to one another. While two of these blades would support sagging lateral vaginal tissue, the closed state of the speculum presents a cylindrical blade structure. What is needed is a speculum having insertable lateral blades, so that the speculum can be inserted into the vagina in a flattened condition, presenting a minimum cross sectional area for ease of insertion and minimum patient discomfort.
U.S. Pat. No. 6,569,091 describes a vaginal speculum consisting of two pivotally interconnected and disconnectable jaws, each of which supports a blade assembly movable in a longitudinal direction. Additionally, one of the blades can be moved circumferentially. Each blade can be completely withdrawn from the speculum, even during the procedure. Circumferential displacement of one of the blades in both directions makes it possible to observe the vaginal cavity over the entire periphery without rotating the entire speculum or replacing it with another tool. However, to permit such circumferential movement, both the blade and the jaw on which it is mounted are arcuate in shape, with the jaws being shown as coming together to form a cylinder split into halves along its axis. What is needed is a speculum including connectable blades for retaining prolapsed tissue without placing such requirements on the shape of the speculum in it closed condition, in which it is inserted into the vagina.